Digital lighting technologies, i.e. illumination based on semiconductor light sources, such as light-emitting diodes (LEDs), today offer a viable alternative to traditional fluorescent, HID, and incandescent lamps. Recent advances in LED technology coupled with its many functional advantages such as high energy conversion and optical efficiency, durability, and lower operating costs, has led to the development of efficient, robust, and precisely controllable full-spectrum lighting sources.
Consequently, existing systems for natural illumination based lighting control, occupancy-based lighting control, and security control are able to utilize digital lighting technologies to more precisely monitor and control architectural spaces such as offices and meeting rooms. Existing natural illumination based lighting control systems may, for example, employ individually controllable luminaires with dimming or bi-level switching ballasts as well as one or more natural illumination photosensors to measure the average workplane illumination within a naturally illuminated space. In such systems, one or more controllers, in order to respond to daylight egress and maintain a minimum workplane illumination, may monitor the output of one or more photosensors and control illumination provided by the luminaires.
Also, conventional occupancy-based lighting control systems may utilize advances made in digital lighting technologies by employing individually controllable luminaires with dimming or switched ballasts in conjunction with one or more occupancy sensors that utilize ultrasonic transducers or pyroelectric sensors to determine whether an illuminated architectural space, such as an office, is occupied. In such systems, one or more occupancy controllers may monitor the output of the occupancy sensors and dim one or more of the luminaires when the sensors indicate that the space is unoccupied. Similarly, existing security control systems may comprise one or more digital video cameras as well as controllers, to record and monitor the output of the cameras. Existing security control systems may therefore detect and alert security personnel to potential security breaches.
Along with advances made in the field of digital lighting technologies, significant advances have been made in the field of imaging technologies, particularly image sensor technologies. As a result, image sensors are easily integrated into devices such as digital cameras, they are sophisticated enough to capture very high resolution images, and are able to demonstrate light sensitivities comparable to that of the human eye. Moreover, advances in the realms of computer networks and microprocessors have made distributed processing a reality. Networked systems that continually produce content rich data such as high-resolution images, may, as a result, gain easy access to the computing or processing capacity necessary to efficiently process large quantities of content rich data.
Despite advances made in the realms of digital lighting technologies, image sensing technologies and distributed processing, existing security control systems as well as natural-illumination-based and occupancy-based lighting control systems have failed to leverage the combined benefits provided by these advances. The failure to leverage these benefits has consequently resulted in significant disadvantages for the users of such systems. For example, while such existing systems may be able to more precisely control architectural spaces because they are able to leverage the benefits of digital lighting technologies, because such systems do not additionally leverage the benefits provided by advances made in the realm of image sensing technologies, they are unable to provide the combined functions of natural illumination based lighting control, occupancy-based lighting control, and security control. Users wishing to acquire a combination of such functionalities are therefore forced to invest in separate systems, which results in increased installation and maintenance costs.
Further, because existing natural illumination based lighting control systems, occupancy-based lighting control systems and security control systems do not leverage advances made in image sensing and distributed processing technologies, such systems are not amenable to being programmatically adjusted in response to changing environmental conditions, such as changes in the arrangement of furniture within architectural spaces. For example, existing natural illumination based lighting control systems typically comprise a silicon photodiode and an associated amplifier mounted in a housing with a focusing optic and an opaque shield, resulting in a fixed field of view that can only be modified by physically tilting or rotating the housing.
Moreover, because existing systems for security control as well as systems for natural illumination based and occupancy-based lighting control do not leverage the computing power of networked processors, they are limited in their abilities to provide the essentially constant data gathering and processing required in order to closely and efficiently monitoring heavily utilized architectural spaces.
As a result, there exists a significant need in the art to simultaneously leverage advances made in the realms of digital lighting technologies, image-based sensing technologies and networked or distributed processing technologies in order to provide users with cost effective systems that provide the combined benefits of lighting control based on changes in natural illumination and occupancy, as well as security control. Such systems could utilize digital lighting technologies to individually control luminaires in response to changes in natural illumination or occupancy. Such systems could additionally utilize image-based sensors, such as the sensors used by digital cameras, to rapidly generate image data capable of providing information relating to natural illumination, occupancy, as well as security. Finally, such systems could also utilize multiple networked processors to efficiently process the generated image data in order that heavily used and therefore constantly changing spaces may be closely monitored and controlled.